Most Populous Cities of the World

The biggest cities to ever exist

For the first time in human history, a majority of people live in urban environments. The world's largest cities today fall under a class that researchers call "megacities," with a population of over 10 million people. Of the more than 7 billion people on Earth, 7% of them live in megacities. Learn a bit more about these massive settlements, how they compare, and how we got our rankings.

Shanghai may be China's largest city following 1990's economic reforms, but its resident speak their own minority language. Shanghainese uses its own rules for writing, and when spoken is mutually unintelligible with Mandarin.

Beijing is one of the oldest cities in China, with plenty of history to show. Among its many historic sites, the first Peking Duck restaurant (which opened in the 1400s) still operates in the city today.

Mexico City, identified as the Federal District (Distrito Federal) until 2016, is the oldest capital and largest city in the Americas. The city is also one of only two capitals to be founded by Amerindians, the other being Quito, Ecuador.

On top of its feudal history and powerful economy, Osaka's most prominent facet is its food culture. Osaka has historically been an important trade region for crops, and the foods from Osaka are some of the best loved in all of Japan. This metropolitan area also encompasses the historic cities of Kobe and Kyoto.

Cairo has led two very different lives, and led much of the world with it. The Ancient Egyptian capital of Memphis is contained in the modern city, which itself was the capital of the Fatimids and Ayyubids from the 900s-1200s.

New York's reputation and reach are outsize for its age. People have lived around New York for a long time, but the city (then New Amsterdam) wasn't founded until the 1600s, making it one of the youngest on the list.

Perhaps coming as a surprise due to the region's ancient history and importance to the Mughals, the city of Karachi is the youngest city on this list. It was founded in 1723 to protect Omani interests.

Buenos Aires is one of the wealthiest, most vibrant, and most diverse cities in the world. It might rank even higher on our list if it didn't share the banks of the Rio de la Plata with Montevideo, another beautiful city right across the bay.

Kolkata is yet another beautiful city in India, home to artists and intellectuals. One crowd you're more likely to find here than elsewhere, though, is fans of India's top two Association Football teams, East Bengal and Mohun Bagan.

Most people know that Istanbul was Constantinople, but many people aren't aware of the name's origin. From the Greek eis tan polin, "to the city," the name marks the city's history and importance in the Eastern Mediterranean.

Chongqing may not be as large as Beijing or Shanghai, but during the Second Sino-Japanese War it was at the heart of Chinese resistance against the Japanese occupation, earning its nickname as the City of Heroes.

Lagos was once a small port, and an infamous center in the slave trade. Despite not being a singularly administered city, and not the capital of Nigeria, Lagos has grown to become the largest and wealthiest city in Africa.

Manila, from the start, has been intercultural; the city was chartered by Spain after taking it from Brunei, who seized it from China. These influences have led to Manila having some of the world's most beautiful and unique architecture.

Another wartime capital of China, in this instance Guangzhou was the final mainland bastion of the Republic of China against the PLA. This connection to Taiwan helped the city greatly when China opened up trade.

Among former colonies, Rio de Janeiro has a very unique claim to fame. This coastal city became the capital of the governing Portuguese Empire, when the court relocated. It was then the capital of the Empire of Brazil.

Source: United Nations, Department of Economic and Social Affairs, Population Division (2016).

What's a City?

While people will generally agree that a city is a close area with a lot of buildings and people, defining what counts as a city for demographic purposes can be tricky. Per World Urbanization Prospects, there are three basic ways to determine a city: there's the city proper, which is just the legal bounds of the city itself; there's the urban agglomeration, which includes all connected urban or densely settled areas around the city; and then there's the metropolitan area, which includes the range of suburbs and communities wherein much of the population regularly commutes into the city. Most of these numbers are urban agglomerations, but some are not, either due to tradition or due to particular characteristics about that city. The city with the widest disparity between these figures is Jakarta, with about 10,000,000 in the city proper and 30,000,000 in the agglomeration.

The Urban World

According to the most recent figures from the United Nations, over 50 percent of the world's population lives in an urban environment. That number is expected to reach 60 percent by 2030. Today, 23 percent of the population lives in cities exceeding one million in population, and 7 percent of the population specifically lives in megacities of more than ten million. There are 512 cities with at least 1 million people, but only 31 megacities.

Of megacities, a substantial majority are in the Global South. China is home to six megacities, and India has five. China and India collectively account for 7 of the 20 cities on our list. Japan, Brazil, and the United States are the next best represented with two megacities apiece, and 5 on our list.

What's Changing?

The most substantial changes in urban populations have been in China and sub-Saharan Africa. China has been undergoing rapid urbanization since the restructuring of their economy in the latter portion of the twentieth century. By 2030 China is expected to attain yet another megacity, marking a clear departure from its agrarian past. 20 major cities in China are currently growing at double the global average rate.

In Africa, three new countries will host megacities within the next decade and a half: Johannesburg in South Africa, Luanda in Angola, and Dar-es-Salaam in Tanzania. Additionally, the cities of Lagos, Nigeria and Kinshasa, DRC are projected to continue their meteoric rise, going from 17th and 23rd place to 9th and 12th, respectively. This can likely be attested to improved access to health services, and the nations' increasing shares of global GDP.